Research into Australian Thoroughbred racing suggests that 17% of racehorses retire each season and 2.1% die.
Kshitiz Shrestha and his fellow researchers at the University of Melbourne, writing in the open-access journal PLOS ONE, said the destinations of Thoroughbreds exiting racing is a high-profile issue, with ethical and welfare implications for both animal welfare groups and racing regulators.
The study team set out to investigate the reasons that Thoroughbreds temporarily or permanently exited racing and training in Australia in the 2017–2018 racing season, and the outcomes for these horses after racing.
An online questionnaire was sent to the last registered trainers of a representative sample of 2509 “inactive” Thoroughbreds.
Inactive horses were defined as those listed as “active” but had not trialed or raced in the last six months of the season, or who had an inactive status recorded in the Racing Australia database.
Of the 1750 responses received, the largest group comprised Thoroughbreds that had permanently exited the racing industry, either through retirement (45%) or death (5.3%).
A relatively large group – 43% – had exited racing only temporarily, and participated in the racing industry the following season.
“The reasons for retirement were predominantly voluntary, such as poor performance or owner’s request,” the researchers reported.
Almost one-third of retirements were because of injuries, with tendon or ligament problems the most frequently listed conditions.
The median age of the 780 study horses categorised as retired was five years. Females were 1.2 times more likely to be retired than males. Geldings were 7.2 times more likely to be retired compared with stallions.
The median age of retirement at five for females was significantly less than the median retirement age for males, at six.
The most frequently reported activities undertaken by retired or re-homed horses were equestrian or pleasure horse activities (45%), followed by those that went on for breeding. “These two categories accounted for three-quarters of all retirement outcomes.”
The researchers found that males were more likely to retire to undertake equestrian or pleasure pursuits than females. Conversely, females were more likely to retire to breeding careers.
Extending the survey results to the wider population of Thoroughbreds that raced or trained in Australia in the 2017–2018 season (37,750 horses in all), indicates that 17% of the population retire each year and 2.1% die.
The researchers found that 90 of the 96 horses reported as deceased in their survey had died because of injury or illness, with only one recorded as deceased because of behaviour.
Of the three horses categorised as sent to an abattoir, all were geldings. The reason given for being sent to an abattoir were behavioural issues in one case, and an unspecified injury or illness during training in the other two cases.
An injury incurred while exercising was the most frequently cited individual circumstance leading to death (54%, or 49 of 90) collectively, with those dying during a race (24) the most frequent, followed by deaths while training (19) and while participating in a trial (6).
Musculoskeletal injuries were the most frequently cited injury or illness leading to death (54%, 49 of 90), with fractures the most frequent individual injury. The majority of fractures occurred during exercise.
Injuries and illnesses included surgical complications (2 horses), with single deaths arising from cancer, electrocution, foaling issues, an eye cyst, a suspected snakebite, a blood clotting disorder, and a multi-drug resistant infection.
Trainers were not able to provide the specified injury or illness leading to death for 5% (5 of 96) of deceased horses.
Discussing their findings, the researchers noted that previous Australian and New Zealand studies have reported that most retirements were voluntary in nature, often due to poor performance or owner requests, which is similar to the findings reported in the current study.
The relatively consistent age of retirement, together with the majority of horses retiring for voluntary reasons, suggests the decision to retire is not entirely dependent on biological or physiological effects, but rather is due to an accumulation of factors, including horse performance and other industry-level effects.
The authors noted that the permanent outcomes in terms of retirement or death for the Thoroughbreds in this study was lower than previous Australian research. “This is likely due to the inclusion of temporary stable exits in the estimates from previous research.”
The median age of horses being voluntarily retired at five is contrary to the belief that horses are forced to retire mainly due to injury, they said.
The information gathered provides a benchmark to assist with resourcing and evaluating programs aimed at incentivising traceability of Thoroughbreds moving outside its jurisdiction into the wider horse industry, the researchers said.
The University of Melbourne study team comprised Shrestha, James Gilkerson, Mark Stevenson and Meredith Flash.
Shrestha K, Gilkerson JR, Stevenson MA, Flash ML (2021) Drivers of exit and outcomes for Thoroughbred racehorses participating in the 2017–2018 Australian racing season. PLoS ONE 16(9): e0257581. https://doi.org/10.1371/journal.pone.0257581